Process and apparatus for fiber band spinning

ABSTRACT

The broken thread is returned to the spinning chamber by releasing the thread from the displacing guide means in response to a break while forcing the thread sidewise out of the nip of the doffing rollers. The thread reserve is thus free to be drawn back into the spinning chamber under the suction force created by the chamber.

United States Patent [151 3,680,300 Landwehrkamp 1 Aug. 1, 1972 [54] PROCESS AND APPARATUS FOR [56] References Cited FIBER BAND SPINNING UNITED STATES PATENTS [72] Inventor: Hans Landwehrkamp, Ingolstadt,

Germany 2,924,931 2/ i960 Kuhnrrch et al. ..57/85 3,354,627 11/1967 Cizek et a1. ..57/58.89 X [731 Asslgnw 3,455,095 7/1969 Makeham et al. ..57/5s.s9 x

many

[22] Filed: Nov. 30, 1970 Primary ExaminerWerner H. Schroeder pp NO: 93,552 Attorney-Kenyon & Kenyon Reilly Carr & Chapin [57] ABSTRACT [30] Foreign Application Pnomy Data The broken thread is returned to the spinning 1969 Germany 19 60 562-0 chamber by releasing the thread from the displacing guide means in response to a break while forcing the LS. Cl- R, thread idewise out of [he of [he doffing rollers, 57/156 The thread reserve is thus free to be drawn back into [51] Int. Cl. ..D0lh 15/00, DOlh l/l2 the Spinning chamber under the suction force created [58] Field of Search.....57/34 R, 58.89, 5891, 58.93, by the chamber 13 Claims, 7 Drawing Figures PATENTEDAU: 1 I972 3,680,300

sum u or 7 INVENTOR. HfiAE-J Lmvb WE HRKAMP P'A'TE'N'TEDAus' 11912 SHEET 5 BF 7 INVENTOR.

Hmvs LANDWEHRKAMP v PROCESS AND APPARATUS FOR FIBER BAND SPINNING This invention relates to a process and apparatus for fiber band spinning. More particularly, this invention relates to a process and apparatus for the automatic return of a thread end to the fiber collecting surface of a fiber band spinning machine.

Heretofore when spinning fiber into thread in a fiber band or open-end spinning machine, it has been known to create a yarn reserve outside the fiber collecting surface of the machine in the direction of the doffing rollers so that, upon an occurrence of a drop in thread tension emanating from the fiber collecting surface, the thread end can be returned to the fiber collecting surface for piecing.

In order to return the thread end to the fiber collecting surface of the spinning machine automatically, a number of structures have been attempted. For example, as shown in US. Pat. No. 3,354,631, a reversing of the doffing rollers and the spooling mechanism has been used to return the necessary length of thread or, in French Pat. No. 1,550,189, with a thread reserve above the doffing rollers, a reversing of the doffing rollers independently of the spooling mechanism has been used to return the thread end. However, apart from the substantial technical expenditure necessitated by such individual control or actuation of each spinning part, if a thread breaks and rewinding is necessary, the masses to be declerated and accelerated have been so high that these structures, while suitable for rewinding after stopping the entire spinning machine, react too slowly for piecing a thread after a break occurs. Thus, before pulling of the thread can be stopped, the broken thread end has already left the spinning machine and must again be guided into the delivery tube of the machine. Another structure (as in German Pat. No. 1,288,965) in which a thread reserve of a size sufficient for renewed spinning has been located between the collecting surface and the doffing rollers has also been known. However, this also reacts too slowly and, because of the mass and particularly high spinning speeds, the discharge of the thread can not be inter rupted. Furthermore, the thread reserve mechanism in this latter structure has made servicing difficult. Also, in principle, the deviation of a thread upstream'of the doffing rollers is unfavorable because large frictional forces appear at the deviation locations asa result of the spinning tension. However, if rollers are used, then the mechanism becomes more expensive, and the masses become increased, to the detriment of reaction speed. Furthermore, the building-up of the thread reserve ahead of the doffing rollers produces a variation of the thread number as a result of nonuniform doffing speed, or else the build-up has to take place over a long period of time, during which the mechanism is not in a position to return the thread reserve needed for respinning. Furthermore, an arrangement as in German Democratic Republic Pat. No. 65,362 is not satisfactory in this respect, because the use of rollers in the deviating guidance ahead of the doffing rollers obstructs the rapid release of the thread reserve, or in the case of a thread reserve beyond the doffing rollers, requires additional control or actuation of the rollers so as to release the thread by a rapid lifting of the pressure-applying rollers. The greater the force needed for such a release, the more sluggishly does the apparatus respond.

Accordingly, it is an object of the invention to return a broken thread end as rapidly as possible to the col lecting surface of a spinning chamber without interrupting the spooling or winding-up of the thread.

It is another object of the invention to return a broken thread end to the collecting surface of a spinning chamber without effecting the reversal of mechanical parts.

It is another object of the invention to automatically return a broken thread to a spinning machine in a simple relatively inexpensive manner.

It is another object of the invention to be able to return a broken thread into a high speed spinning machine in a simple manner without reversing any mechanical parts.

It is another object of the invention to provide a system for returning broken threads from a number of spinning locations of a spinning machine for a common starting-up of spinning after a stoppage of the machine.

Briefly, the invention provides a method and apparatus in which a thread reserve is created for a spinning machine and is released for backfeeding into the spinning chamber of the spinning machine under the suction force of the spinning chamber.

The method includes the steps of creating a thread reserve downstream of a set of doffing rollers used to doff the thread from the spinning chamber and of substantially instantaneously releasing the thread from the thread reserve while removing the thread from the nip of the dofi'ing rollers upon the occurrence of a thread break. in this way, it is possible for the thread which is completely free to snap back into the spinning chamber under the suction force created by the chamber during operation. A very rapid response is thus obtained which response is substantially independent of the thread doffing speed.

The apparatus of the invention has a thread displacement guide means which is disposed downstream of the doffing rollers, relative to the direction of thread movement, to create an extended path for the thread and thus a reserve loop or thread reserve. This means further is constructed to substantially instantaneously release the thread reserve in response to the detection of a drop in thread tension by a sensing element located adjacent the spinning machine. In addition, a thread ejector is disposed upstream of the doffing rollers and substantially parallel to the dofiing rollers to cooperate with the thread displacement guide means. The thread ejector serves to move the thread out of the nip of the doffing rollers upon the detection of the drop in thread tension by the sensing element.

. In operation, for example, during a spooling operation should a thread break occur in the spinning machine, the tension in the doifed thread decreases. This causes the thread displacement guide means to release the thread reserve by allowing the thread to be thrown off from the guide means. The thread ejector also forces the thread out of the nip of the doffing rollers. As the thread reserve is then free of restraint, the suction force created by the spinning chamber then draws the thread end rapidly back into spinning chamber for piecing.

Advantageously, the thread reserve can be built up substantially in the plane of the nip of the doffing rollers so as to simplify manipulation of the reserve while saving space.

The invention provides an apparatus which is extremely simple and inexpensive and which operates practically free of inertia.

In order to facilitate the guidance of the thread and the dimensioning of the thread reserve, two fixed-location thread guides can be disposed downstream of the doffing rollers so that the thread reserve is built up therebetween.

In order to make it possible to repeat the build-up of the yarn reserve loop at one or more spinning sites, a plurality of thread displacement guide means of a number of spinning sites can be movable in common in the direction of the reserve loops with each being movable. The guide means can be fixedly mounted and a movable thread displacer may be provided for placing the thread over the guide means. The initial position of such thread displacers can be adjustable in order to allow dimensioning of the length of the piece of thread to be returned. The thread displacers are advantageously disposed at a'number of spinning sites upon a common bar, and are movable with this,in the longitudinal direction of the spinning machine, by means of a common drive mechanism. Since the thread displacement guide means can be made with a run-on surface, so as to facilitate placement of the reserve loop, the need for a special guiding device is eliminated. If the thread-ejector is made as a clamppart, with which a fixed-location stop is associated as a counter-part, then during stoppage of the spinning mechanism the thread can beheld ready for the resumption of spinning, and can be prevented from emerging out of the spinning mechanism. A mechanism required for lifting the clotting rollers is also eliminated.

These and other objects and advantages of the invention will become more apparent from the following detailed description and appended claims taken in conjunction with the accompanying drawings in which:

FIG. 1 shows in a schematic representation the principle of the invention;

FIG. 2 shows a perspective view of an apparatus according to the invention;

FIG. 3 shows another embodiment of the invention;

FIG. 4 shows an enlarged detail of an apparatus of the invention for the building up of the reserve loop with movable thread displacement guide means;

FIG. 5 shows a modified apparatus for the building up of a reserve loop, in a direction perpendicular to the longitudinal axis of a spinning machine;

FIG. 6 shows a perspective view of a detail of the thread displacement guide means of FIG. 2; and

FIG; 7 illustrates an electronic control for the apparatus of FIG. 2.

With the knowledge that the known processes and mechanisms for the automatic respinning of thread at individual spinning places so as to eliminate a thread break are much too complicated and expensive, from the economic point of view, an automatic elimination of thread breaks is without interest. If an apparatus works rapidly enough, then an emergence of the broken thread-end out of the spinning mechanism can be prevented, and the use of an expensive mechanism for returning the thread end into the spinning mechanism can be avoided. However, in order to do this, it is necessary that the feeding back of the thread end shall be effected as free of inertia as possible; that is, actuating the thread should not require any movements of bulky and heavy parts. It has been found that the most rapid and most reliable reaction occurs when the thread end is subjected, in an entirely free manner, to the pulling tension produced produced through the subnormal pressure in the spinning mechanism, and is left to that pull. For this reason, the thread reserve is not fed back by a suitable movement of the threadguiding elements used for displacing the thread, instead the reserve loop is released from the displacement means holding it, by being thrown off. The thread end, being subjected to the pull produced by the underpressure in the spinning chamber, snaps back into the spinning chamber.

Because the thread reserve is advantageously built up downstream of the doffi'ng rollers, in order to reduce the frictional load resulting from the spinning tension on the displacement guide means, it is necessary to release the thread held between the doffing rollers. This is ordinarily done by raising the pressure-applying roller of the doffing rollers. To do this, however, requires a powerful mechanism, which is correspondingly expensive and does not operate in an inertia-free fashion. Thus, the thread is instead forced out substantially parallel to the nip line of the doffing rollers and is thus released for return into the spinning mechanism.

The principle of this process is shown in FIG. 1, with elimination of all machine elements that do not participate directly in this process. The thread F, emerges from a spinning mechanism 8 through a thread-delivery tube 81 and is directed by way of a pair of doffing rollers, consisting of an elongated lower cylinder 5 and a pressure-applying roller 51, to a thread displacement guide means .1 and from there to a thread-guide 31 and beyond that to a wind-on spool 6. During a spinning operation the thread F thus assumes the position shown by the solid line.

An ejector 2 is disposed upstream (i.e. below) the doffing rollers 5, 51 and is movably mounted so as to be brought into one position 2' by means of a magnet 23 and into a further position 2". The ejector 2 is movable by means of a bar 22, which can be displaced in the direction of the arrow P Where a number of spinning sites are used, a plurality of corresponding ejectors can be mounted in common on the bar 22. In position 2", the ejector 2 presses against a fixed-location clamp abutment 21. A sensing element or feeler 7 is disposed between thethread-delivery tube 81 and the doffing rollers 5, 51 which checks the tension of the thread F. As soon as the thread tension diminishes, which is a sign that the thread end is no longer connected to the fiber ring in 'the spinning mechanism, this feeler 7 produces a contact that actuates the thread displacement guide means 1 and also the ejector 2. For example, the thread-displacement guide means 1 is pulled back by a magnet 14, so that the thread is thrown off. At the same time, by means of a magnet 23, the ejector 2 is moved into position 2', so that the thread no longer runs into the nip of the doffing rollers 5, 51. The thread reserve is thus released immediately, and becomes drawn back into the spinning chamber through the underpressure therein. At this moment, the thread F assumes the position F shown by the dotted line. When contact with the fibers ring in the spinning chamber is thus restored, the tension in the thread increases. The

' contact of feeler 7 is interrupted again, and the ejector 2 returns to its initial position. In addition, the thread F, which is now again under the normal spinning tension, is pulled immediately laterally into the nip of the doffing rollers, and once more is subjected to a controlled withdrawal. The thread now takes the shortest path between the doffing rollers 5, 51, and the spool 6 until a new thread reserve is formed.

Also, for a resumption of spinning after an interruption of operations, it must be possible to feed back a thread reserve. During a stoppage of the spinning mechanism, the thread F should not slide out of the thread delivery tube 81. For this reason, stoppage is effected in such a way that after shut-down, but while the spinning mechanism is running down, the bar 22 is operated. The ejector 2 thus arrives in its farthest position 2", and the thread F is forced out of the nip of the doffing rollers 5, 51, and becomes clamped against an abutment 21. During the stoppage of the spinning mechanism, the thread F therefore assumes its position F", shown by a dot-dash line. At the start-up of the spinning mechanism, the spinning chamber initially starts operating. Thereafter, the thread-feed, the doffing rollers and the winding mechanism for the spool are switched on. At the same time, the clamping of the thread F against the abutment 21 is eliminated, in'that the ejector 2 is moved by the bar 22 toward the right as viewed. The thread-feeler 7 thus finds that the spinning tension is lacking, so that, at this same moment, the thread displacement guide means 1 is pulled back, and the ejector 2 by means of the magnet 23 assumes its position 2'. In spite of the shift of the bar 22 into its original position, the thread F is not yet able to run into the doffing rollers 5, 51. It is only when the thread end, drawn back into the spinning chamber 8, has resumed contact with the fiber ring, that, as a result of the spinning tension, the contact belonging to the feeler 7 becomes interrupted, as described above for the case of thread breakage, so that the ejector 2 returns from its position 2' to its original position, and

the thread F runs into the nip line of the doffing rollers The build-up of the thread reserve can be accomplished in various ways. For example, referring to FIG. 3, the thread displacement guide means 11 are disposed on a common bar 15, which can move in the direction of the arrow P In order to build up the thread reserve, the bar 15 is first moved so far to the right that the displacement guide means 11 comes to rest at the right against the thread F. Then, the bar 15 is moved again to the left into its original position, so that the thread is displaced by the guide means 11 into a loop.

Alternatively, referring to FIG. 4, the thread displacement guide means 1 is disposed in a fixed location, and can be pulledback bya magnet 14 as-is known only for the purpose of throwing off the thread loop. For better and quicker returning of the thread F into the dofflng rollers, a thread guide 3 is disposed directly beyond the doffing rollers 5, 51. The thread reserve loop is formed by means of thread displacers 4 constituted by a pair of pins disposed fork-fashion on a movable bar 41 situated above the entire length of the machine. In operation, directly after the release of the thread reserve by the guide means 1, the thread is reintroduced into the nip line of the doffing rollers 5, 51. The thread displacers 4'then move from their position 4 shown by dot-dash lines to the left to push the thread F to the left until it comes to lie over the thread displacement guide means 1. For this purpose, the bar 41 can be moved in the direction of the arrow F, by means of a drive mechanism, for example by means of a motor 43, which engages by a pinion 44 in a set of teeth in the bar 41. Instead of the motor 43 with pinion 44, it is also possible to provide a cam drive or a crank drive for moving the bar 41.

The movement of the thread displacers 4 is also initiated by the interruption of the feeler contact when the spinning tension is again obtained. The thread-displacers 4 then lays the thread over the guide means 1, and returns to the original position 4 so that a reserve is formed between the thread-guides 3 and 31. By the aid of this bar 41, which is able to move in the longitu dinal direction of the machine, it is possible to actuate in common all the displacers 4 for a number of spinning sites.

The length of reserve thread needed for automatic start-up depends, among other things, on the material and on the doffing speed. It is therefore desirable to make a central adjustment of the reserve length for all the spinning sites of the machine. This is achieved in that either the initial position 4' of the thread displacer 4 is adjustable, so that the thrown-off thread loop is released not for its entire length but'only for a part of it with a residual deviation due to the displacer 4 or else the magnitude of the lifting movement of the thread displacement guide means 11 (FIG. 3) is adjustable through the drive of the bar 15.

Referring to FIG. 2, the ejector 20 andthe thread displacement guide means 10 can also be coupled directly with one another as through the intermediary of a three-arm lever mechanism. A fork-shaped dis-' placement guide means 10 is mounted on one lever arm 16 while the ejector 20 is mounted on a second lever arm 24. A magnet 18 acts by an armature 19 on a third lever arm 17. The three lever arms 16, 24, 17 are fastened on a vertical shaft 25 to rotate with the shaft 25. In operation, the thread displacer 4 pulls the thread F into a reserve loop, and lays it over the guide means 10. So that the thread F can be laid better and without guidance over the guide means 10, the guide means 10 is provided with a run-on surface 13 which deflects the thread into position. The thread F can thus become pushed through the displacer 4 over the guide means 10.

If the feeler 7 determines that there is a diminution of the thread tension, the feeler 7 closes the circuit for the magnet 18. The armature 19 presses against the lever 17, whose pivoting movement is transmitted to the two other levers 16 and 24. Through this, the thread-displacement guide means 10 is pulled back in opposition to a fixedly mounted stripper 9, so that the reserve loop is thrown off. At the same time, the ejector 20 forces the thread P out of the nip line of the doffing rollers 5,51, so that the reserve loop can be drawn back into the spinning mechanism 8. As soon as the spinning tension is reached, the feeler 7 interrupts the circuit of the magnet 18, and the ejector 20, together with the guide means 10, are, via a spring 26, brought back into their original position. In addition, the thread displacer 4 comes into operation for the'purpose of forming a new thread reserve by laying the thread F upon the displacement guide means 10.

In order to control the various magnets and operating motors a suitable electrical circuit can be provided. For example, referring to FIG. 7, the feeler 7 has a contact which is closed in its fundamental position, that is, when the thread tension is correct, through which a switch-unit 62 is interrupted (or open) and the magnet 18 is in a nonexcited state. If, through a diminution of the thread tension, the feeler 7 becomes interrupted, then the switchunit 62 is closed, and supplies a brief pulse to the magnet 18 in order to cause a throwing off of the reserve loop and to cause a forcing of the thread F out of the nip line of the doffing rollers 5, 51. The thread F, by means of the lower-pressure prevailing in the spinning mechanism 8, is drawn back into the mechanism 8 and the connection with the fibers fed into the spinning mechanism 8 by a feed device 82 is restored. If this connection cannot be produced within a certain interval of time, then the switch-unit 62 actuates a magnet 83 for stopping the feed device 82, until the thread doffing tension is again restored at the feeler 7.

In principle, the buildup of the thread reserve can be accomplished in two ways:

a. Dependent on the feeler 7. In this case, by means of the switch-unit 62 another switch-unit 63 becomes switched in, and remains switched in until the buildup of the thread reserve is completed. This switch-unit 63 operates a motor 64 for the needed length of time which through the intermediary of a pinion 65 drives the bar 41 formed as a toothed rack.

b. At regular intervals of time, for example, intervals of 3 minutes each. The periodically operating control device 66 then periodically emits suitable signals to the switch-unit 63 which then, as described, actuates the bar 41 through the motor 64.

This arrangement is also suitable for resuming spinning after a standstill of the machine. In this case, the thread F remains in the nip of the dofiing rollers 5, 51 during standstill and thus is prevented from emerging out of the thread delivery tube 81. At the startingup of the machine, and after the spinning chamber 8 first goes into operation, the pressure-applying roller 51 is raised before release of the thread reserve is effected, and after this release is set on again. This is done, for example, by means of a cam 54 which is able to turn with a shaft 55 and presses against the free end of a lever 52 which is able to pivot about an axle 53 and which carries the pressure-applying roller 51 thereon. Since the ejector 20 is actuated at the same time as the release of the thread reserve, the thread F is brought out of the reach of the doffing rollers 5, 51 during the lift of the pressure-applying roller 51 so that immediately after the immediately-following setting on of the pressure roller 51, the thread F remains outside the nip. Consequently, this results in the same conditions as if there had been a release of the thread reserve during the elimination of a thread break during the running of the machine. The start-up of spinning now proceeds as has been described above. After contact with the fibers ring in the spinning chamber is resumed, the normal spinning tension is produced in the spinning chamber,

and the magnet 18 becomes currentless. The thread F is thus no longer prevented by the ejector 20 from running into the nip of the doffing rollers 5, 51.

It may happen that, through the spooling operation or other influences, the thread tension diminishes briefly and thereby the thread loop accidentally falls off the thread displacing guide means 10. Thus, in order to insure against accidental running off of the thread, the displacing guide means 10 as shown in FIG. 6 is provided with a delimiter of the thread path in the form of a triangular eye 12. This eye 12 is arranged so that the moving thread F cannot run off over the free end of the guide means 10. Furthermore, the eye 12 is fastened elastically to the stripper 9, so that the thread displacer 4 can push it aside for the purpose of laying the thread F on the guide means 10.

Referring to FIG. 7, the cam 54 can, for example, be driven by a motor 56, whereby the motor 56 comes into operation by means of the main switch arrangement 57 at the starting-up of the machine. This main-switch device 57 also controls in a chronologically correct sequence, the setting into operation of the spinning chamber 8, of the feed device 82, and so forth.

In the described embodiments, in order to conserve space, the thread reserve is built up parallel to the iongitudinal axis of the machine so as to be situated substantially in a plane going through the nip of the doffing rollers. The purpose of the invention, is however, not dependent on this arrangement. To this end, referring to FIG. 5, a horizontal spinning mechanism 8 has the thread reserve loop disposed outside the nip plane and perpendicular to the longitudinal axis of the machine. The thread reserve is, as has already been described, by means of displacers 4 laid over a thread displacing guide means I, and thrown off therefrom for feeding back into the spinning mechanism 8. The displacers 4 are fastened on a bar 42 which can be moved perpendicularly to the longitudinal axis of the machine. In order to allow the movement of the displacers of a number of spinning sites through the intermediary of a common drive device, a shaft 45 is disposed parallel to the doffing rollers 5, 51, and a pinion 44 for each spinning site is fastened thereon. Each pinion 44 is connected with the bar 42 by means of teeth thereon. In order to place the thread F on the thread displacement guide means 1, the bar 42 can be moved to and fro in the direction of the arrow P by the pinion 44, Here too, a common adjustment of the position of displacement for dimensioning the length of the fed-back thread F is possible. Prior to its release and during normal spinning operations, the thread F assumes the position shown in solid lines, whereas after the release of the thread reserve, the thread runs as shown by the line F over the displacer 4 and the thread-guide 31 before being wound on the spool 6 by way of the spooling roller 61. For the rest, the functioning of the parts is the same as has already been described.

The invention is not limited to the forms of construction shown. These merely represent examples for explaining the principles of the invention. It is easily possible to interchange individual elements of the illustrated forms of construction. For example, in the case of the design of FIG. 5 instead of using the thread displacer 4, it is possible to use the movable thread displacing guides 11 according to FIG. 3. It is also possible, for example, to replace the retractable thread displacing guide means 10 by one that is fixed in location opposite which the stripper 9 is movable, by means of a suitable coupling to the lever arm 16.

The invention thus provides an automatic means of returning a broken thread to a spinning machine for piecing. The apparatus provided is relatively inexpensive and, as such, does not have any substantial effect on the overall cost of the spinning machine.

It is to be understood that the terminology of spinning chamber for which the invention is applicable includes pneumatic operating spinning as spinning rotors (of U.S. Pat. No. 3,440,812), rotatable or fixed spinning funnels (Czech Pat. No. 87,947 and Japanese Patent application 38/24,05l) or chambers in which the fibers moving with a medium join a freely rotating thread end(U.S. Pat. No. 2,911,783).

What is claimed is:

1. In combination with a spinning machine for spinning fiber into thread within a spinning chamber and doffing rollers defining a nip for withdrawing thread therethrough from said spinning chamber, an apparatus for returning a broken thread to said spinning chamber including a thread displacing guide means disposed downstream of said doffing rollers relative to the doffing direction of the doffed thread for guiding the doffed thread through a thread reserve loop to form a thread reserve, said means having means for releasing the thread therefrom; and

a thread ejector disposed upstream of said doffing rollers relative to the doffing direction of the doffed thread, said thread ejector being movably mounted to pass through the plane of said nip in parallel relation to said doffing rollers to force the doffed thread from between said doffing rollers.

2. The combination as set forth in claim 1 which further includes sensing means for sensing tension in the doffed thread adjacent said spinning chamber and means responsive to said sensing means for moving said ejector through said plane of said nip to force the thread therefrom and for actuating said releasing means to release the thread from said thread reserve.

3. The combination as set forth in claim 1 wherein said guide means includes a pair of guides downstream of said doffing rollers for guiding of the thread thereover and a thread displacing means between said guides for forming of said thread reserve between said guides.

4. The combination as set forth in claim 1 which further includes a plurality of said thread displacing guide means corresponding to a plurality of spinning mechanisms mounted in common for movement in the from said thread reserve is adjustable,

7. T e combination as se orth m claim 5 WhlCh further includes a plurality of said spinning mechanisms, a plurality of said displacers mounted on a common bar movably mounted in the longitudinal direction of said spinning machine, and a common drive for driving said bar.

8. The combination as set forth in claim 5 wherein said guide means includes a run-on surface facing said displacer for deflecting the thread moved by said displacer over said guide means.

9. The combination as set forth in claim 1 wherein said ejector is a clamp and which further includes a fixedly mounted abutment, said ejector clamp being movable against said abutment to clamp a thread therebetween.

10. The combination as set forth in claim 1 wherein said guide means and said ejector are coupled together for movement in common, and which further includes a fixedly mounted stripper adjacent said guide means for stripping a thread from said guide means upon movement of said guide means relative to said stripper.

11. The combination as set forth in claim 10 which further includes a delimiter adjacent said guide means for retaining the thread on said guide means against accidental release therefrom.

12. A method of automatically returning a broken thread to a spinning chamber of a spinning machine comprising the steps of doffing a thread from the spinning chamber through a nip of a set of doffing rollers downstream of the spinning chamber;

creating a thread reserve downstream of the set of doffing rollers;

releasing the thread from said thread reserve in response to the breaking of the thread in said spinning chamber while forcing the thread out of said nip whereby the doffed thread is free to be drawn back into said spinning chamber.

13. A method as set forth in claim 12 wherein said thread reserve is built-up substantially in the plane of said nip.

UNITED STATES PATENT OFFICE CERTIFICATE OF COECTION Patent No. 3,680,300 Dated August 97 Hans Landwehrkamp Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column -1, line 5, "produced produced" should be --produced--.

Column 9, line 15, "38/2 4,051" should be Signed and sealed this 9th day'of January 1973.

(SEAL) Attest:

EDWARD M. PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents FORM PO-1050 (10-69) USCOMM-DC 60376-P69 Q U.S. GOVERNMENT PRINTING OFFICE: (969 O-36G-334 

1. In combination with a spinning machine for spinning fiber into thread within a spinning chamber and doffing rollers defining a nip for withdrawing thread therethrough from said spinning chamber, an apparatus for returning a broken thread to said spinning chamber including a thread displacing guide means disposed downstream of said doffing rollers relative to the doffing direction of the doffed thread for guiding the doffed thread through a thread reserve loop to form a thread reserve, said means having means for releasing the thread therefrom; and a thread ejector disposed upstream of said doffing rollers relative to the doffing direction of the doffed thread, said thread ejector being movably mounted to pass through the plane of said nip in parallel relation to said doffing rollers to force the doffed thread from between said doffing rollers.
 2. The combination as set forth in claim 1 which further includes sensing means for sensing tension in the doffed thread adjacent said spinning chamber and means responsive to said sensing means for moving said ejector through said plane of said nip to force the thread therefrom and for actuating said releasing means to release the thread from said thread reserve.
 3. The combination as set forth in claim 1 wherein said guide means includes a pair of guides downstream of said doffing rollers for guiding of the thread thereover and a thread displacing means between said guides for forming of said thread reserve between said guides.
 4. The combination as set forth in claim 1 which further includes a plurality of said thread displacing guide means corresponding to a plurality of spinning mechanisms mounted in common for movement in the direction of the respective thread loops.
 5. The combination as set forth in claim 1 wherein said guide means is fixedly mounted and which further includes a movable thread displacer for moving a thread disposed downstream of said doffing rollers in a direction substantially perpendicularly to the doffing direction of the thread into position over said guide means.
 6. The combination as set forth in claim 5 wherein said displacer has an adjustable initial position whereby the length of thread released to said spinning chamber from said thread reserve is adjustable.
 7. The combination as set forth in claim 5 which further includes a plurality of said spinning mechanisms, a plurality of said displacers mounted on a common bar movably mounted in the longitudinal direction of said spinning machine, and a common drive for driving said bar.
 8. The combination as set forth in claim 5 wherein said guide means includes a run-on surface facing said displacer for deflecting the thread moved by said displacer over said guide means.
 9. The combination as set forth in claim 1 wherein said ejector is a clamp and which further includes a fixedly mounted abutment, said ejector clamp being movable against said abutment to clamp a thread therebetween.
 10. The combination as set forth in claim 1 wherein said guide means and said ejector are coupled together for movement in common, and which further includes a fixedly mounted stripper adjacent said guide means for stripping a thread from said guide means upon movement of said guide means relative to said stripper.
 11. The combination as set forth in claim 10 which further includes a delimiter adjacent said guide means for retaining the thread on said guide means against accidental release therefrom.
 12. A method of automatically returning a broken thread to a spinning chamber of a spinning machine comprising the steps of doffing a thread from the spinning chamber through a nip of a set of doffing rollers downstream of the spinning chamber; creating a thread reserve downstream of the set of doffing rollers; releasing the thread from said thread reserve in response to the breaking of the thread in said spinning chamber while forcing the thread out of said nip whereby the doffed thread is free to be drawn back into said spinning chamber.
 13. A method as set forth in claim 12 wherein said thread reserve is built-up substantially in the plane of said nip. 